The Pueblo year in pollen

Pollen seasons in Pueblo: tree pollen March to June, grass May to July, and ragweed from early August until the first frost, around October 9.

Tree pollen
Grass
Ragweed
Ragweed's bar ends at the typical first frost — around October 9.

When does ragweed season end in Pueblo?

Ragweed season in Pueblo typically ends with the first frost, around October 9. Some years it comes as early as October 4, some as late as October 14.

A light frost around October 9 knocks the season down; the hard freeze that finishes it usually follows by October 18. Based on 30 years of NOAA frost records (1991–2020).

The rest of the Pueblo pollen year

AllergenTypical season
Juniper March to May
Cottonwood and aspen March to May
Maple (boxelder) March to May
Birch and alder April to May
Pine May to June
Grass May to July

Season-by-season detail is on the Colorado page.

Nearby calendars

Frost dates for Pueblo come from the Pueblo Mem Airport weather station's 30-year records. Season windows reviewed August 2026.